Apparatus for manufacturing electric cables



E. P. BARRETT Original Filed June 23, 1932 APPARATUS FOR MANUFACTURING ELECTRIC CABLES May 2, 1939.

INVENTOR E. P. BARRETT A TTORNEY UNITED STATES PATENT OFFICE APPARATUS FOR MANUFACTURING ELECTRIC CABLES Elliott P. Barrett, Pittsburgh, Pa., assignor to Western Electric Company, Incorporated, New York, N. Y., a corporation of New York Original application June 23, 1932, Serial No. 618,861, now Patent No. 2,121,942, dated June 28, 1938. Divided and this application October 9,

1936, Serial No. 104,810

11 Claims. (Cl. 11333) Thi i ti relates t an apparatus for tape, before it is applied over the insulated conmanufacturing electric cables and more particuductor P larly to an apparatus for manufacturing a type Fig. 3 is an enlarged partial end view of the of cable for use in communication deforming or corrugating rollers shown in Fig. 6 Objects of the invention are to provide an im- 1 o Corrugat t e ap proved apparatus formanufacturing electric cable 4 a v c l secti n l view o a cable by continuous process. taken along the line 4-4 of Fig. 5, and

The present invention is a division of that dis- 5 is a P Vie partially in e o Of O e closed and claimed in copending application Seembodiment the C e. l rial No. 618,861 filed June 23, 1932 (now Patent Referring to the drawing (Figs. 4 and a No, 2,121,942, June 28, 1938) by the present inplurality of conductors 0, pr f r y of copper ventor. and having low resistance, insulated with paper, In the prior art it has b n th practice i some textile or other suitable material and preferably instances in connection ith th manufacture twisted together in pairs are stranded together 16 of cables for transmitting intelligence electrically ly in lay rs t f rm a r p or undl 15 to form the cable by stranding pairs of paper in- The group or bundle l2 may be formed in any sulated conductors together, binding the con- Suitable manner but preferably y the s a n ductor pairs in a grou a d finally extruding a well known form of strander, which has assosheath of lead or lead alloy over the insulated, elated therewith a p serving d y which 0 conductors. a paper wrapping l3 may be applied spirally to 2 If in place of the lead sheath thi metal retain the group comprising the conductors withsheath of copper, zinc, or similar metal is applied in a predetemlined diameteras a tape directly over a group ofassembled con- A supply reel N (Fig. 1) containing a len ductors havin it abutti edges secured in a of the paper covered conductor group I5 is manner to providea water-proof cable joint, the mounted on su u p ng members I6. tape may have a tendency to rip and crack if th Another supply reel 11 containing a length of a assembled cable is flexed beyond certain limits. suitable metallic e I 8 such as brass, p e According to one embodiment of the invention Zinc tape s preferably mounted on supporting herein illustrated and described, an apparatus is members A p o c u atin o ers 2 and provided having means for forming pairs of paper 23 are P ly mounted on the supporting in t conductors, binding t pairs of members is, .(a portion of one of which has been tors into a group, covering the group it shown cut away) to form a corrugated metal tape layer of paper applied helically, applyin a de- 24, the'corrugations preferably extending the enformed metal tape around t conductor core, t tire width of the tape and at right angles to the deformation preferably having the form of or intape as shown in when the edges the eluding embossings or corrugations transverse to tape 4 are to be lapped and solder ed after the the insulated conductor portion, and the edges of tape is formed around the conductor group I5, th tape longitudinal t t conductor portion they are preferably coated with solder along the and soldering or otherwise joining the edges of edges, as shown at 20 and 2| in a he solder 40 the metal tape together to form a water-tight costing ispreferably applied tethe edges before 40 cable sheath and applying a suitable protecting the Corrugating Operationcoating over the deformed metal tape such as n forming corrugatmg rollers 22 and 23 rubber or a wrapping of a textile material impreg- (Flgsand are preferably constructed so that nated with a preserving material. they will form corrugations by an approximately 4,5 pure bending operation and without appreciably Other objects and advantages of the invention 1 elongating the metal tape l8 and to form corruwill a l appe r from the fol owing detalled descflp gations having approximately the shape of a sine w commered in connection with the wave. In a particular embodiment the following g l l i drawing, which dimensions for the rollers were found satisfac- 8- 5 an 99% on View of one embodl' tory for producing corrugations having the above ment of an apparatus, with a portion thereof cut characteristics in tape approximately .005 in away, for forming an electric cable such as shown thick; outside diameter 1.006 in.; 30 teeth with in Figs. 4 and 5; straight sides .030 in. wide, .05 in. deep and .015 Fig. 2 is a plan view of one embodiment of the in. radiusat ends thereof, distance between cendeformed tape having corrugations transverse to ters of adjacent teeth .1 in. at a distance of .478

' curve one side in. from the roller centers. corrugating rollers having these dimensions will produce a corrugated tape having approximately .1 in. between corrugations extending in the same direction and approximately .05 in. between the upper and lower corrugations, when the teeth of one roller are kept centered in the spaces between the teeth of the other roller.

A forming roller having a half-round peripheral groove therein and a forming shoe 26 are provided so that the conductor group I5 can be forced against the central portion of the corrugated tape 24 to form or curve the bottom or central portion of the tape. A forming roller 21 having a half-round peripheral groove therein and a guide roller 28 are provided to form or of the corrugated tape 24 around the insulated conductor group I5 and another similar forming roller 29 with its associated guide roller 30 are provided to form or curve the other side of the corrugated tape 24 around the insulated conductor group 15. A suitable device 3| is provided to join the edges of the corrugated tape 24 in order to form a water-tight joint between the edges of the tape. Where the edges of the tape are to be lapped and have been previously coated with solder, this device may take the form of a tube 32 heated to melt the solder and secure the edges of the tape together to form a water-tight joint. Obviously, if the edges of the tape 24 are to be joined by welding or brazing the heated tube 3| may be replaced by suitable apparatus to hold the tape edges together and weld or braze them to form a water-tight joint. A take-up spool 33 is preferably provided to receive the assembled corrugated tape covered conductor group. The take-up spool 33 and the corrugating rollers 22 and 23 may be driven through suitable driving means from a suitable source of power such as a motor 34.

The operation of the device as shown in Fig. l

is as follows:

As the motor 34 rotates the take-up spool 33, the paper covered conductor group i5 is drawn from the supply reel M. The rotation of the corrugating rollers 22 and 23 causes the metal tape l8 to be .drawn from the supply reel I! through the rollers and forms the corrugated tape 24 which passes between the forming roller 25 and the forming shoe 26. The paper'insulated conductor group I5 is drawn between the forming roller 25 and forming shoe 26 above the central portion of the corrugated tape 24. As the forming roller 25 is curved the paper covered conductor group I5 is forced against the cormgated tape 24 and forms the central portion of the corrugated tape 24. As the corrugated tape 24 and the conductor group I5 pass between the forming roller 21 and its associated guide roller 28, one side of the corrugated tape 24 is formed and as the conductor group and corrugated tape pass through the forming roller 29 and its associated guide roller 30 the other side of the corrugated tape is formed. As the conductor group with the corrugated metal tape formed around it pass through the device 3| the edges of the tape are joined to form a cable which is water-tight and shielded from extraneous inductive interference. In the corrugated sheath thus made, the corrugations are complete rings around the sheath, as clearly indicated in Fig. 5, each corrugation being independent of any other. Hence if the corrugated sheath be damaged by external force or accident water or any other foreign substance so permitted to enter is paper 36 dammed back at the first undamaged corrugation instead of being led along as would be the case if the corrugation were a continuous spiral. Damage by accident is thus confined to the immediate neighborhood of an injury.

In some instances it is preferable to apply a non-metallic covering over the corrugated tape. A suitable protective coating (Figs. 4 and 5) such as tough rubber, gutta percha, or gutta percha substitute, may be applied by forcing the cable through an extruding machine of any suitable type well known in the art which applies a covering in one or more layers around the entire length of the cable or the protective coating may take the form of a textile material impregnated with a suitable preserving compound preferably such as asphalt flooded burlap wrapped around the cable andv covered with a layer of spirally applied over the impregnated textile material. The textile material may be impregnated either before or after being applied to the cable and the preserving compound may be asphalt or any other similar compound capable of resisting chemical decomposition and also serving as a mechanical reenforcement for the cable.

The above described means for forming an electric cable provide a flexible cable which when flexed will cause the sheath 24 to crinkle uniformly and the finished cable can withstand many flexures and may be flexed to a greater degree without the tendency of the water-tight sheath 24 to rip or crack. The fact that the corrugated sheath 24 touches the smoothly cylindrical, wrapped core l2, l3 substantially only at the bottoms of the troughs of the corrugations (as clearly shown in Fig. 5) is one reason for the greater flexibility of the completed cable as compared with some cables of the prior art in which corrugations have been pressed into a completed smoothly cylindrical sheath, and in which the corrugations are pressed into and filled with the insulating material of the core.

It is to be understood that the invention is not to be limited to the particular embodiments shown, nor to the particular arrangements that have been described and shown in detail, but

only by the scope of the appended claims.

What is claimed is:

1. In an apparatus for making a flexible, watertight and electrically shielded electric cable, sup-- ply means for a metal tape, supply means for a central cable portion containing a conductor, a pair of corrugating rollers for corrugating the tape transversely without appreciable elongation, means for forming the tape around the central cable portion and longitudinally thereof, means for securing the edges of the tape together to form a continuous and water-proof sheath, take-up means for the sheathed cable, and means for driving the corrugating rollers and the take-up means.

2. In an apparatus for making a flexible, water-tight and electrically shielded electric cable, supply means for a metal tape, supply means for a central cable portion containing a conductor, a pair of corrugating rollers for corrugating the tape transversely, means for forming the tape around the central cable portion and longitudinally thereof, means for securing the edges of the tape together to form a continuous and water-proof sheath over the central cable portion, take-up means for the sheathed cable, and means for driving the corrugating rollers and the take-up means.

- insulated conductive core, means to crimp with- 3. In an apparatus for making a flexible, water-tight and electrically shielded electric cable, supply means for a corrugated metal tape, supply means for a central cable portion, means for forming the tape around the central cable portion, means for Joining the edges 01' the tape to form a continuous and water-proof sheath, take-up means for the sheathed cable, and means for driving the take-up means.

4. In an apparatus for making a flexible watertight and electrically shielded electric cable means to supply a metal tape, means to supply an insulated conductive core, means to form transverse corrugations in the edges of the tape together to form a continuous transversely corrugated water-proof sheath about the core.

5. In an apparatus for making a flexible watertight and electrically shielded electric cable means to supply a metal tape, means to supply an out materially elongating the tape to form transverse corrugations therein, means to form the corrugated tape longitudinally into a sheath around the core, and means to Join the edges of the tape together to form a continuous transversely corrugated water-proof sheath about the core. I

6. In an apparatus for making a flexible watertight and electrically shielded electric cable means to supply a metal tape, means to supply an insulated conductive core, means to form transverse corrugations in the tape, means to form the corrugated tape longitudinally into a sheath around the core, and means to solder the edges of the tape together to form a continuous transversely corrugated water-proof sheath about the core.

7. In an apparatus for making a flexible watertight and electrically shielded electric cable means to supply a metal tape, means to supply an insulated conductive core, a pair of coacting toothed rollers to form transverse corrugations in the tape, means to form the corrugated tape 1ongitudinally into a sheath around the core, and means to join the edges of the tape together to form a continuous transversely corrugated waterproof sheath about the core.

8. In an apparatus tight and electrically shielded electric cable means supply an insulated conductive core, coacting toothed rollers to form transverse corrugations in the tape, the teeth on each roller each being about 61. wide and 10t high and rounded at the top thereof with a radius of about 3t and the teeth on each roller being spaced apart about t from center to center, means to form the corrugated tape longitudinally into a sheath around the core, and means to join the edges of the tape together to form a continuous transversely corrugated water-proof sheath about the core.

le having a. transversely corrugated metallic tape formed into a sheath, means to transversely corrugate a metallic tape comprising a pair of coacting toothed rollers, the teeth on 9. In an apparatus for forming a cab on each roller being spaced apart about 20t from center to center, means to form the corrugated tape longitudinally into a sheath around the core, and means to join the edges of the tape together to form a continuous transversely corrugated water-proof sheath about the core.

10. In an apparatus for forming a cable having a transversely corrugated metallic tape formed into a sheath, means to transversely corrugate a metallic tape, and means to form the corrugated tape longitudinally about an insulated conductive core, the said forming means comprising a forming roller having a peripheral groove therein to receive the tape and the core upon the tape, a pressure member to force the core and tape into the groove of the roller to form the central portion of the tape about the core, a guide roller to receive the core and tape from the said forming roller and to support the same, a

core while on the second guide roller.

11. In an apparatus for forming a cable having 

